PEMB Shallow Foundation Types

[HDStructural]

Hello all,

I wanted to get some thoughts on the pros and cons of two shallow foundation types for PEMBS.

1. Spread footings with piers which support the PEMB columns. Exterior wall footings. All footings go down below frost depth. Floating slab-on-grade inside the building.

2. One large slab with turned down slabs at the edges. Turn down will extend down below frost depth. At the PEMB columns, the thickened slab area would be wider than normal to give more bearing area.

I have generally seen the first type from my experience in the commercial/aviation/light industrial industries.

What do you see most commonly? Is one better than the other in terms of schedule or price?

Thanks

 

[phamENG]

Number 2 is most common in my area (Coastal Virginia). To get the uplift and sliding resistance you need out of shallow spread footing means that footing will be massive. If you frost depth is very deep you might have more luck, but here we have a frost depth of 8" here the shallow footing is very shallow.

 

[DaveAtkins]

Either will work. If you use Method 1, you need hairpins to take the thrust into the slab-on-grade, or else the spread footings become larger than they need to be, as phamENG mentioned.

DaveAtkins

 

[HTURKAK]

I have experience with both types .
I have preferred type two for small bldgs , say the span is less than say 12 m . Sometimes it is necessary to provide separate footings for each equipment ( say pumps , vibrating eq. ) and it would be necessary to provide type 1.
My suggestion would be i if both methods viable , compare the costs.
...........


He is like a man building a house, who dug deep and laid the foundation on the rock. And when the flood arose, the stream beat vehemently against that house, and could not shake it, for it was founded on the rock..

Luke 6:48